Slipknot is an American heavy metal band from Des Moines, Iowa. Formed in September 1995, the group was founded by percussionist Shawn Crahan and bassist Paul Gray. After several line-up changes in their early years, the band settled on nine members for more than a decade: Corey Taylor, Mick Thomson, Jim Root, Paul Gray, Craig Jones, Sid Wilson, Shawn Crahan, Chris Fehn and Joey Jordison. Gray died on May 24, 2010, and was replaced from 2011 to 2014 by former guitarist Donnie Steele. Jordison departed from the band on December 12, 2013. The reason for this is still debated. Steele left during the recording sessions for .5: The Gray Chapter as he wanted to focus on getting married. The band is now touring with replacement musicians Alessandro Venturella on bass and Jay Weinberg on drums. After the departure of Jordison, the only founding member left in the current lineup is percussionist Shawn Crahan, however, all of the other remaining members in the band have been a part of it since their 1999 eponymous debut.
In the years before Slipknot formed, a state of shifting band membership existed throughout the metal scene in Des Moines, Iowa. In 1991, the biggest metal band in Des Moines was Atomic Opera, with Jim Root on guitar. Drummer Joey Jordison founded a thrash metal band called Modifidious, playing at a club called Runway. Modifidious opened for Atomic Opera on December 1, 1991, at the Runway, after which their guitarist left for the more successful Atomic Opera. Jordison replaced him with local guitarist Craig Jones.